This study addresses the need for detailed accounts of how English language learners engage in face-to-face interaction in naturally occurring English language mediated contexts, its aim being to enlarge the SLA and language and migration databases and to inform ESOL teaching practice, materials, curriculum, and assessment design, and institutional policy. Focusing on two forced migrants and a seven-minute service encounter in a hardware store, and employing ecological and sociocognitive theory and co-ethnographic methods drawn from a range of strategies, including linguistic ethnography, nexus analysis, and multi modal interactional analysis, the study investigates how actors align their histories of practice to contexts of interaction, viewing contexts broadly, as co-occurring processes involving objects, built environments, interaction orders, and other social actors, and all processes as the products of their own semiotic histories. The study also explores participants' understandings of such interaction, how it matters to them, what they invest in it, and why. Findings include profound differences between participants in terms of the issues under investigation, differences linked in the study to personal and cultural histories of practice. And here analysis suggests the important role of affect in influencing evaluation, action, adaptation to new (and in this case liminal and largely migrant-populated) environments, and thus to the use/learning of language. Also observed was the importance of communicative-rather than narrowly linguistic-competence, with competence heavily reliant on domain- and genre-relevant resources, a finding which has clear implications for pedagogy. The study therefore indicates an important role for co-ethnography as a pedagogic method and, given the profound differences disclosed both in subjects and contexts and the limited scope of microethnographic study, suggests the need for further research in this area.